Fractional occupation numbers and self‐interaction correction‐scaling methods with the Fermi‐Löwdin orbital self‐interaction correction approach

Fredy W. Aquino, Ravindra Shinde, Bryan M. Wong*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

15 Citations (Scopus)

Abstract

We present a new assessment of the Fermi-Löwdin orbital self-interaction correction (FLO-SIC) approach with an emphasis on its performance for predicting energies as a function of fractional occupation numbers (FONs) for various multielectron systems. Our approach is implemented in the massively parallelized NWChem quantum chemistry software package and has been benchmarked on the prediction of total energies, atomization energies, and ionization potentials of small molecules and relatively large aromatic systems. Within our study, we also derive an alternate expression for the FLO-SIC energy gradient expressed in terms of gradients of the Fermi-orbital eigenvalues and revisit how the FLO-SIC methodology can be seen as a constrained unitary transformation of the canonical Kohn–Sham orbitals. Finally, we conclude with calculations of energies as a function of FONs using various SIC-scaling methods to test the limits of the FLO-SIC formalism on a variety of multielectron systems. We find that these relatively simple scaling methods do improve the prediction of total energies of atomic systems as well as enhance the accuracy of energies as a function of FONs for other multielectron chemical species.
Original languageEnglish
Pages (from-to)1200-1208
JournalJournal of computational chemistry
Volume41
Issue number12
Early online date11 Feb 2020
DOIs
Publication statusPublished - 5 May 2020
Externally publishedYes

Keywords

  • n/a OA procedure

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